ABSTRACT / SUMMARY Despite reports of the strong killing function of NK cells more than four decades ago, adoptive therapy strategies to exploit this property against late-stage cancer cells have had limited success in the clinic. A major obstacle to translation has been the lack of reliable methods to enhance the inadequate persistence and reduced activity of NK cells after their infusion into patients. Thus, the long-term goal of Project 3 is to devise novel adoptive cell-based therapies for advanced B-lymphoid malignancies (such as acute lymphoblastic leukemia, chronic lymphocytic leukemia and non-Hodgkin lymphoma). The central hypothesis is: (i) the killing function of cord blood (CB)-derived NK cells against hematologic cancers can be substantially enhanced with minimal adverse toxicity, including graft-vs.-host disease, by genetically modifying the cells to express a CD19- specific chimeric antigen receptor (CAR), a suicide gene (inducible caspase-9, or iC9) and the IL-15 cytokine to support NK cell proliferation and durability; and ( ii ) it may be feasible to boost this activity by inhibiting the CISH gene, thus abolishing a pivotal cytokine signaling checkpoint in NK cells and making it possible to consider the use of lower doses of cell therapy without loss of efficacy. This combined strategy, based on our recent preliminary findings as well as the transformative successes with CAR.CD19-redirected T cells, will be pursued in three specific aims. In Aim 1, a first-in-human phase I/II clinical trial, we will evaluate the safety and antitumor activity iC9/CAR.19/IL15-transduced CB-NK cells in 36 patients with advanced leukemia or lymphoma. Aim 2 seeks to track the in vivo fate of the transduced cells described above and correlate the findings with disease responses recorded in Aim 1. This approach will enable us to address several fundamental issues that have been persistent barriers to more effective modes of adoptive NK cell therapy for patients with cancer. Finally, Aim 3 will target CIS, a cytokine signaling checkpoint in NK cells, to further improve the therapeutic potential of our strategy. If we succeed in avoiding toxicity (cytokine release syndrome, for example) that may be associated with targeted therapies of this type, our project will mark a clear advance in the development of novel cellular treatments for cancer.